Aggregate Statistics by Auto Scaling Group

You can aggregate statistics for the EC2 instances in an Auto Scaling group. Amazon
CloudWatch cannot
aggregate data across Regions. Metrics are completely separate between Regions.

This example shows you how to get the total bytes written to disk for one Auto Scaling
group.
The total is computed for one-minute periods for a 24-hour interval across all EC2
instances in the
specified Auto Scaling group.

To display DiskWriteBytes for the instances in an Auto Scaling group using the console

Select the row for the DiskWriteBytes metric and the specific Auto Scaling group,
which displays a graph for the metric for the instances in the Auto Scaling group.
To change the name of the graph,
choose the pencil icon. To change the time range, select one of the predefined values
or
choose custom.

To change the statistic, choose the Graphed metrics tab.
Choose the column heading or an individual value, and then choose one of the statistics
or predefined percentiles, or specify a custom percentile (for example, p95.45).

To change the period, choose the Graphed metrics tab.
Choose the column heading or an individual value, and then choose a different value.

To get DiskWriteBytes for the instances in an Auto Scaling group using the AWS CLI